The present disclosure relates to a method of manufacturing a structural object using a rapid prototyping technology and the structural object.
From the past, a modeling apparatus using a rapid prototyping technology has mainly been used for professional use. As main methods thereof, there are stereolithography, laminated object manufacturing, and modeling with powders. The stereolithography is a method for forming a three-dimensional shape by irradiating a light-curable resin with laser to form a cross-sectional shape of the shaped object, layer by layer and then laminating them. The laminated object manufacturing is a method for forming a three-dimensional shape by cutting out thin sheets, layer by layer, in accordance with the cross-sectional shape of the shaped object and then bonding and laminating. The modeling with powders is a method for forming a three-dimensional shape by laying a layer of powder material to form a cross-sectional shape of the shaped object, layer by layer and then laminating them.
The modeling with powders is roughly divided into methods of melting or sintering powders, and those of solidifying using an adhesive. The former forms the cross-sectional shape by irradiating nylon material, for example, with a laser. The latter solidifies powder material containing gypsum as the main component by ejecting the adhesive to the powder material using an inkjet head, and forms the cross-sectional shape.
In the modeling with powders with the use of an inkjet head, a head of a commercially available inkjet printer is used, and operates on a sheet in which the gypsum powder has been laid as if printing is performed. There is used gypsum as the powder material, and from the print head, the adhesive for solidifying the gypsum is ejected.
Image forming composition described in Patent Literature 1 contains gypsum and a polyvinyl alcohol resin. In the method of manufacturing a three-dimensional structure body according to Patent Literature 1, the above-mentioned image forming composition in powder form is used, its cross-sectional shape is patterned by adding a small amount of water, and the cross-sectional layers thereof are laminated. Thus, the three-dimensional structure body is formed. Further, by adding the water and cross-linking agent to the three-dimensional structure body, there can be obtained a three-dimensional structure body having a desired intensity (for example, see paragraphs 0026 and 0031 in the specification of Patent Literature 1).
In addition, contents described in Patent Literature 2 include that, in a modeling method using the modeling with powders, water-soluble material is used as the powder material (for example, see paragraph 0017 in the specification of Patent Literature 2).